Clinical outcomes and predictors of acute cerebrovascular strokes after coronary artery bypass graft surgery

Abstract

Funding Acknowledgements Type of funding sources: None. Background Coronary artery bypass graft (CABG) surgery still carries a significant risk acute cerebrovascular stroke despite advances in anesthetic, surgical and medical managements. Objective To study the risk factors and get the predictors of acute stroke after CABG and study the clinical outcomes during hospitalization and follow up. Methods This retrospective study included 410 patients who underwent CABG at our tertiary care hospital from January 2016 to August 2020. The patients were divided into two groups according to the occurrence of acute cerebrovascular stroke. Results The study included 410 patients with a median age of 60(55-68) years with a male predominance (82.2%). Thirty-one (7.5%) patients developed strokes after CABG. The stroke group had significantly higher initial sequential organ failure assessment (SOFA) score [ 3(2-4) vs. 2(1-3), p=0.002], SOFA after 48 hours [5(1-7) vs. 1(0-2), p<0.001], higher peak blood lactate level [12.5(7.6-14.7) vs. 5.1(3.7-8.5),p<0.001], longer ICU stay [11(6-42) vs. 4(3-5), p<0.001], more ventilator days [10(2-32) vs. 1(1-2), p<0.001], more tracheostomies (38.7 vs. 0, p<0.001) ,longer post ICU ward stay [11(2-57) vs. 5(3-7), p=0.015] and greater hospital mortality (25.8 vs. 0.8, p<0.001) compared to the non-stroke group respectively. Both groups showed insignificant mortality during a follow up period of 41.5(26.5-54.5) months. Multivariate regression revealed that early hospital stroke was independently predicted with carotid artery disease (OR:8.22, 95%CI:2.92-23.1, p<0.001), CPB time (OR:5.64, 95%CI:1.97-16.11, p<0.001), initial SOFA score (OR:1.643, 95%CI:1.194-2.26, p=0.002), prior stroke (OR:4.412, 95%CI:1.286-15.14, p=0.018), postoperative new AF (OR: 3.014, 95%CI:1.158-7.84, p=0.024) and CKD (OR:1.28,95%CI:1.05-3.75, p=0.017). Late cerebrovascular stroke was independently predicted with CAD (OR:9.38, 95%CI:3.72-23.66, p<0.001), postoperative AF (OR: 2.35,95%CI:1.0125-5.41, p=0.016), prior stroke (OR:3.725,95%CI:1.179-11.768, p=0.025), CABG plus valve surgery (0R:7.44, 95%CI:2.75-20.145, p<0.001), HBA1c (OR:1.431, 95%CI:1.071-1.914, p=0.016) and CKD (OR:2.33, 95%CI:1.056-5.165, p=0.036). Conclusion Acute cerebrovascular stroke is a serious complication after CABG and associated with increased mortality, longer hospital stays with multiple morbidities and resources consumption. Appropriate assessment and management of carotid artery disease, and post-operative atrial fibrillation should be routinely implemented to reduce the risk of early and late strokes in patients undergoing CABG.